Do a script to migrate data from 4store to the Virtuoso or Algregraph Triple-store

[syphax-bouazzouni]

Context

See #229

TODO

• Create a unified script to import or export data from 4store to Virtuoso or Algregraph (@syphax-bouazzouni)
• Create a documentation (@syphax-bouazzouni)
• Test it in Testportal (@syphax-bouazzouni )
• Test it in Stageportal (@syphax-bouazzouni )
• Do it in production for BioDivPortal and EcoPortal (@syphax-bouazzouni)
• Do it in production for AstroPortal (@imadbourouche )
• Do it in production for LovPortal (@muhammedBkf)
• Do it in production for AgroPortal (@syphax-bouazzouni)